The influence of Nd contents and particles on the microstructure and mechanical properties of extruded Mg alloys are discussed. Pure Mg and binary Mg-xNd (x = 0.2 wt.%, 0.5 wt.%, 1 wt.%, 2 wt.%, 5 wt.%) alloys were cast and extruded. Hardness and tensile/compression tests were measured on those alloys. The results show that the addition of Nd to Mg leads to improvements in hardness, tensile/compression yield strengths and elongation. However, the Nd has little effect on ultimate strengths and compressibility of Mg alloys. The contributions of strengthening mechanisms to the tensile/compressive yield strength of extruded Mg-Nd alloys are investigated. Mg₄₁Nd₅ phase was distributed in Mg-2Nd and Mg-5Nd alloys after extrusion, which is the main reason that decreased the grain size of Mg-Nd. The tension-compressing yield asymmetry is decreased from 1.8 to 1 with the increased additions Nd in extruded alloys.